Enhanced Structural Control of Soft-Templated Mesoporous Inorganic Thin Films by Inert Processing Conditions

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Mesoporous thin films offer high surface area and efficient transport properties.
• Fabrication typically involves sol-gel chemistry and organic templating, followed by calcination.
• Anisotropic shrinkage during fabrication poses challenges to film porosity and pore structure.

Purpose of the Study:

• To develop a fabrication strategy to minimize anisotropic shrinkage in mesoporous thin films.
• To enhance structural control, porosity, and pore accessibility.
• To demonstrate the improved mass transport properties for applications like enzyme storage.

Main Methods:

• A two-step calcination process: initial high-temperature treatment in argon, followed by air calcination.
• Formation of a transient carbonaceous scaffold to support the inorganic matrix during condensation.
• Characterization of film porosity, pore size, and structural order.

Main Results:

• The two-step calcination significantly reduced anisotropic film contraction.
• A transient carbonaceous scaffold facilitated full inorganic matrix condensation before template removal.
• Resulting mesoporous films exhibited higher porosity, larger pores, and improved porous order.
• Enhanced mass transport properties were observed, demonstrated by lysozyme adsorption.

Conclusions:

• The two-step calcination strategy effectively controls mesoporous thin film structure and reduces shrinkage.
• This method yields films with superior porosity and pore characteristics.
• The enhanced films are suitable for applications requiring efficient mass transport of large molecules, such as enzyme storage.